Shhhh! She Just Turned – 6T

Someone just turned 60!  But I promised my young (very young) wife that I wouldn’t say who it was.  Over the years, as other distinguished family members received puzzles, 7T, 8T+, and 9T to commemorate significant milestones, she patiently waited to be bestowed the honor of yet another milestone puzzle.  This year, I developed a 6T puzzle for her - for no specific reason.  As my wife unwrapped her presents for yet another 29th birthday, she was delighted to finally receive her own milestone puzzle.

It may come as a surprise, but the 6T puzzle is comprised of 6 T-shaped pieces that have to be packed within a 3x3x3 box.  The puzzle was 3D printed with each of the Ts in a different color and an open-top silver box with 6T debossed on the side.  Immediately, you know there is some funny business going on if you are required to pack 6 Ts made with 5 cubes (that’s 30 altogether) into a box that can accommodate 27 cubes.  It quickly becomes obvious that the triangular half-cubes of the pieces have to be leveraged to jam those Ts together.

Although practically a kid, my wife has been around puzzles for a long time and knows a thing or two about solving them.  She tackled the puzzle and quickly demonstrated that the experience that comes with youth could be used to solve this puzzle in less than 30 minutes.  She was very happy to discover that this was not one of those intractable designs (avoid celebrating 80!).

I should mention that Dr. Volker Latussek had designed a Six-T-Puzzle that was made by Rombol, but I don’t believe that it is currently being made.  This puzzle was previously mentioned in the post, Puzzle-A-Month Challenge.

Like a Dead Skunk in Your Tire Well, Some Things Just Don’t Go Away - Completely Broken Soma, Part 2

Last summer, I described a wondrous puzzle design dubbed the Completely Broken Soma (A Whole New Level of Puzzle Abuse - Completely Broken Soma).  I ended the post with a request for information on who would be interested in acquiring a copy if it was made available.  With the collection of comments from the post, I approached the cognoscenti of puzzle craftsmanshipdom to prioritize a queue of craftsman interested in the honor of creating this puzzle.  However, not a one indicated the least bit of interest in creating a puzzle that garnered 0 comments in its unveiling post.  I attempted to argue that the lack of response was due to the fact that nobody reads my blog instead of lack of interest in owning a completely broken puzzle.  Unfortunately, I was not unable to convince any of those venerable craftsmen to put their reputation and resources at risk.  On the bright side, there are no readers to be upset by this news.

The smart thing to do is fling the design deep into the pit of eternal stench.  So I bought a 3D printer and attempted to plasticize the design myself.  I went with the 3 color version and created the design files to print the required 54 half-cubes.  The 48mm (1.9”) cube only took a little over 10 hours to print.

I soon found out that there’s a special place in hell where people can assemble the pieces of the Completely Broken Soma.  The diminutive 8x16x16 mm half-cubes have tiny pimples that need to be popped into the recesses of other half-cubes to connect them.  Forcing these pieces together is a challenge that gets ever more interesting as you add the third and fourth half-cubes while the prior ones get in the way.  However, when you have completed assembling the pieces and then the cube, you are rewarded with a beautiful lumpy cube where the pieces just don’t fit nicely together.  Since the connectors are so small they have a tendency to flex and nice 90 degree joints are not guaranteed (or even likely).

Having suffered a similar fate when creating the wood version, I knew exactly what to do.  I shoved the puzzle in a dehydrator and slowly drove the temperature to just over 130 degrees, the low end of the glass transition temperature for PLA.  I didn’t want to risk going higher and potentially fusing the pieces together.  Shortly after the target temperature was reached, I pulled it out and quickly clamped it for the night.  In the morning, I unclamped a reasonably cubic object and disassembled it to ensure that nothing was unintentionally fused together.  Having finally exorcising that caustic concept from my system, I quickly put it in a box and sent it away to plague someone else.  I really don’t understand why I don’t have friends any more.

A Christmas Present For You 2! – Penultimate Burr Box Set 7-Piece Burr Challenges

I know that by now, most of you have completed all 898 Penultimate Burr Box Set challenges including last year’s Christmas Challenge and were wondering what to do with that old dusty box.  In the event that you haven’t sold, traded, or regifted your stick collection, there is now an entirely new set of challenges for you.

6-Piece burrs have been all the rage with everyone amassing large quantities of this venerable puzzle and all its variants.  However, the 6-piece burr is so 2020!  As we leave 2020 behind us, a new set of challenges is needed for 2021.  Enter the 7-piece burr, 6’s lesser known brother.

Of course, there are multiple ways to construct a shape with 7 burr pieces.  With the construction that I chose, BurrTools indicated there are 3,232,523 assemblies and 184,687 solutions.  In English, this means that there are 3,232,523 ways that 7 of the burr pieces from the set can make the 7-piece burr shape, but only 184,687 of these assemblies can be taken apart.  Further analysis indicates that 471 of the solutions are unique.  A unique solution is one where the 7 pieces cannot be rearranged to make the 7-piece burr another way.  Of the 471 unique solutions, 38 are level 2 and the remaining 433 are level 1, where the level is the number of moves required to remove the first piece or set of pieces from the puzzle.

I haven’t completed all 471 solutions yet.  OK, I’ve only done the first one so far.  I didn’t find it that difficult but it does require some different thinking.  In the 6-piece burr, all the pieces basically perform the same function, however in the 7-piece burr, 2 of the pieces now function differently.  This can be leveraged during the solution process.

First Attempt: During my first attempt, I managed to assemble 6 of the pieces into an assembly that would have accommodated the final piece, but there was no way to add that piece.  Some extra thinking was required to find an assembly that can be constructed.  

Second Attempt: My second attempt was close, but the parity of the last piece was wrong for the assembly that I was constructing.  (sheesh, what does he mean by parity? – Basically, the assembly had a hole on the left and the piece had a cube on the right).  

Final Attempt: Assuming that the final piece was correct, I rebuilt the assembly with a parity to match the piece and it finally went together.

Some of the puzzles will be very similar to each other and you may want to cherry pick ones that look interesting.  Then again, 2 puzzles may only differ by 1 piece yet be entirely different. If you would like to give these a try yourself, the pieces required for the unique solutions are below.  Hopefully, these challenges will keep your set from joining the yuletide log.

Level 2 Unique Solution Piece Sets:

6,7,9,10,15,17,19	6,7,9,10,15,17,20	5,6,7,12,17,22,24	5,6,7,10,21,22,24
5,6,7,12,15,20,22	5,6,7,15,17,23,24	3,5,6,7,8,22,24	6,7,9,10,11,17,24
5,6,7,9,16,19,24	5,7,10,12,15,18,24	5,6,7,9,19,24,25	5,6,7,10,15,23,24
5,7,10,12,17,22,24	5,6,7,9,17,24,26	4,5,6,7,8,22,24	4,5,6,7,11,15,24
5,6,7,15,17,18,24	5,6,7,12,15,17,22	5,6,7,15,17,20,22	6,7,9,10,14,15,19
6,7,9,10,14,15,20	5,6,7,10,20,22,24	5,6,7,10,19,22,24	5,6,7,12,15,23,24
5,7,10,15,17,18,24	6,7,10,11,12,15,17	5,7,10,12,15,17,22	5,7,10,12,15,17,24
5,6,7,10,15,22,26	5,6,7,10,15,24,26	6,7,10,12,14,15,17	5,6,7,17,20,22,24
5,6,7,9,17,23,24	3,5,6,7,11,15,24	5,6,7,12,20,22,24	4,5,6,7,10,15,24
5,6,7,12,15,18,24	6,7,10,13,14,15,17

Level 1 Unique Solution Piece Sets:

5,7,9,10,18,21,24	5,7,9,10,15,18,23	5,7,9,10,15,18,26	5,7,10,11,15,16,19
5,7,10,11,15,16,22	5,7,10,11,15,16,24	1,5,7,8,10,18,22	4,6,7,8,9,10,22
4,6,7,8,9,10,24	1,3,5,6,9,10,15	5,6,7,15,17,21,23	5,6,7,15,17,21,26
5,7,9,10,13,16,19	4,5,7,9,10,15,22	4,5,7,9,10,15,24	5,7,9,10,13,16,20
6,7,9,10,13,15,23	6,7,9,10,13,15,26	1,5,7,9,10,12,19	1,5,7,9,10,12,20
5,6,10,13,17,24,25	5,6,7,11,13,24,26	5,7,10,11,15,18,19	1,5,6,9,10,21,24
5,7,10,14,15,17,18	5,7,9,10,14,19,22	5,7,9,10,14,19,24	5,7,9,10,14,19,25
5,7,10,14,15,17,21	5,6,10,14,15,16,17	1,5,6,10,15,16,17	1,4,5,6,9,10,15
5,7,9,10,16,21,24	5,7,9,10,13,18,19	5,7,9,10,13,18,20	1,5,6,10,14,15,18
1,5,6,10,14,15,19	1,5,7,9,10,14,19	5,7,10,11,13,16,24	1,5,7,9,10,14,20
5,6,10,11,15,19,22	5,6,10,11,15,19,24	5,7,10,11,12,15,21	5,7,10,14,15,19,22
5,7,10,14,15,19,24	5,7,10,14,15,19,25	5,7,9,10,11,16,19	5,7,9,10,11,16,20
5,6,10,14,15,18,22	5,6,10,14,15,18,24	5,7,10,11,17,22,24	3,5,6,7,8,24,25
1,5,7,10,15,16,17	6,7,9,10,11,15,23	6,7,9,10,11,15,26	5,6,7,13,15,18,23
5,6,7,13,15,18,26	5,6,9,10,21,22,24	5,7,10,11,13,18,24	5,7,9,10,15,22,23
5,7,9,10,15,22,26	4,5,6,7,9,17,19	1,5,7,10,14,15,18	1,5,7,10,14,15,19
1,5,7,9,10,16,22	1,5,6,10,11,12,22	4,5,6,7,9,17,20	5,7,9,10,12,19,24
5,6,9,10,17,19,22	5,6,9,10,17,19,24	5,6,9,10,17,19,25	5,7,9,10,14,21,24
1,5,7,8,10,22,25	5,7,9,10,11,18,19	5,7,9,10,11,18,20	4,5,6,7,8,16,24
6,7,8,9,10,22,23	6,7,8,9,10,22,26	5,6,9,10,16,18,24	5,6,7,9,21,23,24
1,5,6,10,12,15,16	1,5,6,10,12,15,19	1,5,6,10,12,15,21	5,7,9,10,13,20,25
5,6,9,10,18,20,24	4,6,7,8,10,14,15	5,7,10,12,15,16,21	5,7,10,12,15,16,22
5,7,10,12,15,16,24	5,6,7,9,20,22,23	5,6,7,9,20,22,26	1,5,6,7,9,13,23
5,6,7,13,17,22,23	1,5,6,7,9,13,26	5,6,7,13,17,22,26	5,7,9,10,15,24,26
1,5,7,9,10,18,24	1,5,6,10,11,14,24	1,5,7,10,11,12,22	5,7,10,11,15,22,25
5,7,10,12,14,15,21	5,7,10,15,17,19,22	5,7,10,15,17,19,24	5,6,10,15,17,18,19
1,5,6,8,10,16,24	1,5,7,8,10,24,25	6,7,8,9,10,24,26	1,4,5,6,7,9,12
5,6,10,15,16,17,18	5,6,10,15,16,17,19	1,5,7,10,12,15,16	1,5,7,10,12,15,19
5,6,10,15,16,17,22	5,6,10,15,16,17,24	5,6,10,15,16,17,25	5,6,9,10,18,22,24
1,5,7,10,12,15,21	5,7,10,12,15,18,21	3,5,6,7,9,12,19	3,6,7,8,10,15,17
3,5,6,7,9,12,20	1,5,7,10,11,14,24	5,7,10,11,15,24,25	4,5,6,7,15,17,19
1,5,6,8,10,18,22	1,5,6,7,8,14,23	1,5,6,7,8,14,26	5,6,10,12,14,16,24
3,5,6,7,15,16,17	5,7,9,10,11,20,25	5,6,9,10,16,20,24	4,5,6,9,10,15,16
4,5,6,9,10,15,17	4,5,6,9,10,15,18	4,5,6,9,10,15,22	4,5,6,9,10,15,24
4,5,6,9,10,15,25	3,5,6,9,10,14,15	5,6,10,11,14,22,24	5,6,9,10,18,24,25
5,6,9,10,12,16,19	1,5,6,9,10,12,19	5,6,10,12,15,19,22	5,6,10,12,15,19,24
5,7,10,11,13,22,24	5,6,7,9,14,19,23	5,6,9,10,12,16,20	5,6,10,12,15,19,25
5,6,7,9,14,19,26	1,5,6,9,10,12,20	1,5,7,9,10,20,22	1,5,7,9,10,20,24
5,6,7,11,15,19,23	5,6,7,11,15,19,26	5,7,10,15,17,21,22	5,7,10,15,17,21,24
5,7,10,15,17,21,25	5,6,7,14,15,18,23	5,6,7,14,15,18,26	5,6,10,12,14,18,24
4,5,6,7,12,14,24	5,6,9,10,16,22,24	4,6,7,9,10,12,15	5,6,9,10,13,19,22
3,6,7,9,10,11,15	5,7,10,13,17,18,22	5,6,9,10,12,18,19	1,5,6,9,10,14,19
5,6,9,10,12,18,20	5,7,10,11,13,24,25	1,5,6,9,10,14,20	4,5,6,7,13,17,24
5,7,10,13,16,17,22	5,7,10,13,15,16,18	5,7,10,13,15,16,19	3,5,6,7,12,15,16
3,5,6,7,12,15,19	3,6,7,9,10,13,15	5,6,9,10,15,23,24	3,5,6,7,9,18,24
1,5,6,9,10,16,22	5,6,10,12,15,21,22	5,6,10,12,15,21,24	5,6,9,10,11,19,22
5,6,9,10,11,19,24	1,5,6,8,10,22,25	5,6,7,9,13,20,23	5,6,7,9,13,20,26
4,5,6,7,8,24,25	5,7,10,13,15,18,19	5,7,10,13,15,18,22	5,7,10,13,15,18,24
5,7,10,13,15,18,25	5,7,9,10,21,22,24	4,5,6,7,11,17,24	1,5,6,9,10,18,24
5,6,9,10,12,20,25	5,7,9,10,17,19,22	5,7,9,10,17,19,24	6,7,8,10,14,15,23
6,7,8,10,14,15,26	5,6,7,11,15,23,25	3,5,6,7,10,15,24	1,5,6,8,10,24,25
5,6,7,8,22,23,25	5,7,9,10,16,18,22	1,3,5,6,7,9,12	5,6,10,13,15,19,22
5,6,10,13,15,19,24	5,7,9,10,18,20,22	5,7,9,10,21,24,25	5,7,9,10,15,17,23
5,7,9,10,15,17,26	5,7,10,13,17,22,25	3,5,6,7,9,20,24	5,7,9,10,14,16,19
5,6,7,9,11,20,23	5,6,7,9,11,20,26	5,7,9,10,14,16,20	5,6,7,11,15,25,26
5,6,7,8,22,25,26	5,6,10,12,14,24,25	5,6,10,11,17,18,24	5,6,7,11,14,24,26
5,7,9,10,18,22,24	5,6,10,11,16,17,24	1,5,7,9,10,11,19	4,5,6,7,9,12,19
1,5,7,9,10,11,20	4,5,6,7,9,12,20	5,6,7,11,13,23,24	1,5,6,9,10,20,22
1,5,6,9,10,20,24	5,7,10,11,15,17,21	5,7,9,10,14,18,19	5,7,10,14,15,16,18
5,7,10,14,15,16,19	5,7,9,10,14,18,20	5,6,10,11,15,16,22	5,6,10,11,15,16,24
5,6,7,11,12,22,23	5,6,7,11,12,22,26	5,6,7,10,15,16,20	5,7,10,11,14,16,24
5,7,9,10,16,20,22	3,5,7,9,10,15,22	3,5,7,9,10,15,24	5,6,7,8,18,22,23
5,6,7,8,18,22,26	1,5,7,9,10,13,19	1,5,7,9,10,13,20	5,6,7,12,15,21,23
5,6,7,12,15,21,26	5,7,10,11,15,19,22	5,7,10,11,15,19,24	5,7,10,11,15,19,25
6,7,9,10,12,15,23	6,7,9,10,12,15,26	5,7,10,14,15,18,19	5,7,10,14,15,18,22
5,7,10,14,15,18,24	5,7,10,14,15,18,25	1,5,6,10,15,17,19	1,5,6,10,15,17,21
5,6,7,10,15,18,20	5,7,10,11,14,18,24	5,7,9,10,16,22,24	5,7,9,10,16,22,25
5,7,9,10,13,19,22	5,7,9,10,13,19,25	1,5,7,9,10,15,23	1,5,7,9,10,15,26
5,6,9,10,17,18,19	5,6,9,10,17,18,20	1,5,6,10,13,15,18	1,5,6,10,13,15,19
5,7,10,11,12,16,22	5,7,9,10,14,20,25	5,6,7,12,14,22,23	5,6,7,12,14,22,26
5,6,9,10,16,17,19	5,6,10,14,15,19,22	5,6,10,14,15,19,24	5,6,9,10,16,17,20
5,6,10,11,17,22,24	1,5,7,10,15,17,19	1,5,6,10,12,14,22	1,5,6,10,12,14,24
5,6,7,13,15,19,23	5,6,7,13,15,19,26	1,5,7,10,15,17,21	1,3,5,7,9,10,15
1,5,7,9,10,17,19	5,7,9,10,15,23,24	5,7,9,10,15,23,25	1,5,7,9,10,17,20
1,5,6,10,11,13,24	4,5,6,7,9,18,24	1,5,6,10,13,17,22	5,7,10,15,17,18,21
1,5,6,10,13,17,24	5,7,10,11,12,18,22	1,5,6,7,8,11,23	1,5,6,7,8,11,26
1,5,7,10,13,15,18	1,5,7,10,13,15,19	5,7,9,10,11,19,22	5,7,9,10,11,19,24
5,7,9,10,11,19,25	6,7,8,9,10,23,24	1,4,5,6,7,8,17	5,6,7,9,21,24,26
5,6,10,11,17,24,25	5,7,10,15,16,17,21	5,7,10,15,16,17,22	5,7,10,15,16,17,24
5,7,9,10,13,21,24	1,5,7,10,12,14,22	1,5,7,10,12,14,24	4,6,7,8,10,15,17
5,6,10,12,15,16,18	5,6,10,12,15,16,19	1,5,6,10,11,15,16	1,5,6,10,11,15,19
3,6,7,8,10,14,15	5,7,9,10,15,25,26	5,6,10,12,15,16,22	5,6,10,12,15,16,24
5,6,10,12,15,16,25	1,4,5,7,9,10,15	1,5,6,10,11,15,25	5,6,9,10,17,20,25
5,6,9,10,20,24,25	1,5,7,10,11,13,24	5,6,7,11,15,16,23	5,6,7,11,15,16,26
5,7,10,12,14,16,22	4,5,6,7,15,16,17	3,6,7,8,9,10,22	3,6,7,8,9,10,24
5,6,10,11,15,22,25	5,6,10,15,17,19,22	5,6,10,15,17,19,24	5,6,10,15,17,19,25
1,5,7,10,13,17,22	1,5,7,10,13,17,24	5,6,7,10,15,22,23	4,5,6,9,10,14,15
5,7,10,11,14,22,24	5,7,10,12,13,15,21	5,7,10,12,15,19,22	5,7,10,12,15,19,24
5,6,10,12,15,18,19	1,5,6,9,10,11,19	1,5,6,9,10,11,20	1,5,6,10,11,17,24
4,5,6,7,9,20,24	1,5,7,10,11,15,16	1,5,7,10,11,15,19	1,5,7,10,11,15,25
5,6,9,10,14,19,22	5,6,9,10,14,19,24	5,7,10,12,14,18,22	5,6,10,11,15,24,25
3,5,6,7,15,17,19	5,7,9,10,11,21,24	4,6,7,9,10,11,15	5,7,10,11,14,24,25
3,5,6,9,10,15,16	3,5,6,9,10,15,17	3,5,6,9,10,15,18	3,5,6,9,10,15,22
3,5,6,9,10,15,24	3,5,6,9,10,15,25	1,5,6,9,10,13,19	1,5,6,9,10,13,20
1,5,7,9,10,21,24	5,6,10,11,13,22,24	1,5,7,10,11,17,24	5,6,7,9,16,22,23
5,6,7,9,16,22,26	5,6,7,14,15,19,23	5,6,7,14,15,19,26	5,6,7,9,13,19,23
5,7,10,11,12,22,25	5,6,7,9,13,19,26	4,5,6,7,12,15,16	4,5,6,7,12,15,19
5,6,10,15,17,21,22	5,6,10,15,17,21,24	4,6,7,9,10,13,15	3,5,6,7,12,14,24
3,6,7,9,10,12,15	5,6,9,10,15,22,23	5,6,9,10,15,22,26	5,7,10,12,15,21,22
3,5,6,7,9,17,19	5,6,10,13,17,18,24	5,7,10,12,15,21,24	5,7,10,12,15,21,25
3,5,6,7,9,17,20	5,6,9,10,12,19,24	5,6,9,10,12,19,25	1,5,6,9,10,15,23
1,5,6,9,10,15,26	5,6,7,9,14,20,23	5,6,7,9,14,20,26	3,5,6,7,13,17,24
5,6,10,13,16,17,24	3,5,6,7,8,16,24	5,7,10,13,15,17,21	5,6,9,10,15,24,26
1,5,6,9,10,17,19	1,5,6,9,10,17,20	5,6,7,9,11,19,23	5,6,7,9,11,19,26
5,7,10,12,14,22,25	1,3,5,6,7,8,17	5,7,10,13,15,19,22	5,7,10,13,15,19,24
5,7,10,13,15,19,25	5,6,10,13,15,18,22	5,6,10,13,15,18,24	5,7,9,10,15,16,23
5,7,9,10,15,16,26	6,7,8,10,15,17,23	6,7,8,10,15,17,26	3,5,6,7,11,17,24
5,7,9,10,20,22,25	5,7,9,10,14,15,23	5,7,9,10,14,15,26	1,5,7,8,10,16,24
5,6,7,11,14,23,24

The Gift That Keeps Giving - The Ottawa Cube

Several years ago, the hosts of the 35th International Puzzle Party indicated that they liked my 4x4x4 interlocking puzzles and asked if I would be interested in designing the Committee gift for IPP35.  This gift is given to each of the hard-working committee volunteers that make the event run smoothly.  Of course, I was honored and immediately said yes.

The development of the IPP35 puzzle was a collaborative effort between several people including the IPP35 hosts, Brett Kuehner and Rob Stegmann, who provided design criteria, reviewed proposed designs, and provided feedback; myself as the designer; world-renowned craftsman Brian Menold from Wood Wonders to make them; and Rob Jones providing support.  The result of this team effort was the Ottawa Cube.

What prompted me to finally write about the Ottawa Cube this week, is the listing of an Ottawa Cube on the Cubicdissection Marketplace.  Only 30 were made and you don’t see them very often.  This particular copy is an unopened spare from IPP35 that has been added to the puzzle auction to support a charity: Community Food Bank of New Jersey.  The winner will not only support those in need but end up with a rare puzzle as well.

Since it would be awkward to describe how wonderfully awesome this puzzle is, I decided to share some of the highlights of the design process:

Round 1 - Something New

The IPP35 hosts approached me 1½ years before the event to design the puzzle.  They were looking for something similar to my 4x4x4 designs and offered the following criteria:

• It should be a new, unproduced design.
• It should not be too expensive to make.
• It should be challenging but not too difficult to solve.

With that guidance, I set about creating 3 new designs and I brought prototypes to IPP34 and the following Rochester Puzzle Picnic (RPP) for the hosts to review.  Each of the designs consisted of a 4x4x4 puzzle built around an initial concept.  These concepts were:

• An entire 2x2 face pushed in for the first move.
• A friction move required for the first move.
• A puzzle consisting of all U-shaped pieces.

After a thorough review by the hosts, they said that’s nice, … , but it’s not what we’re looking for.  They were looking for something more theme related to IPP35 in Ottawa, Canada.

I dubbed the 3 designs - The Reject Series, and they are now even rarer than the Ottawa Cube.  There are only 3 complete sets and I have one of them.

Round 2 - Something Themed

Armed with a pocket full of rejection, I thought about how I would approach a themed puzzle.  I pretty quickly decided on a cube with letters on the side with the following criteria:

• The cube would have to be 5x5x5.  A 4x4x4 cube was just too small and anything larger would be too expensive.
• All the characters used would be on the face of the puzzle and not hidden inside.
• It would be done in two colors with red for the foreground and white for the background to match the Canadian flag.
• Each piece would be a single color and not a combination of the two colors.  Yes, sometimes I like to make things unnecessarily complex for myself.  However, without this restriction, you could take any 5x5x5 puzzle and make it look the way you want and I felt that it would lose the quality of what makes it unique if that was done.

I worked up an initial prototype using live cubes and sent pictures to the hosts for an initial assessment to verify that I was on the right track.  I was glad to get a response back that it looked worth pursuing.

Round 3 - Something More Complex

Unfortunately, there was no way to lay out the letters on the face where the adjacent edges matched color.  To solve this dilemma, I had to up my game and cut the corner cubes at a 45-degree angle to get a different color on each face.  Of course, this was no longer a cubic dissection and I realized that I had probably just shot the expense criteria to hell.  

Did I mention that I imposed a restriction where each of these different color cube halves can’t be part of the same piece?  Needless to say, it was a challenge to develop an interlocking puzzle with purely colored pieces.

I created a BurrTools file of the new design where each cube in the puzzle was represented by a 3x3x3 set of cubes to allow me to cut them in half at an angle.  BurrTools was able to successfully solve the puzzle, which is always welcome feedback.

With a bit of trepidation, I sent the BurrTools file out to the team for review.  I was particularly worried about what Brian would have to say about all those 45-degree angle cuts.  As an amateur wood dabbler, it looked insurmountable to me.  

Round 4 - Final Product

With the design process complete, Brian Menold took over the development of the Ottawa Cube. Aside from some recommended changes to improve the structural reliability of the pieces from Brett and Rob’s review of an initial prototype, it was good to go.  Rob also suggested the name: The Ottawa Cube.

The final product is a gorgeous cube with the letters for IPP35 on 5 of the 6 faces.  It’s made with Redheart and Maple to represent the red and white colors of the Canadian flag.  It’s also fairly big and heavy at slightly over 3” per side.

When I first saw the Ottawa Cube at IPP35, I was amazed on how beautiful they looked and how smoothly they moved.  Brian did an amazing job with the 45-degree angled pieces and I was impressed on how well everything came together.

I’m sure that Brian has his own story to tell about unrealistic designers and constraints.  After everything was done and I chatted with Brian about the project, I thought I heard him mumble something under his breath like “neber eggen”.

I’m glad to have been part of The Ottawa Cube team and thoroughly enjoyed working with the team.  I hope that others will be interested in acquiring a copy and helping support the Community Food Bank of New Jersey by bidding generously on the Cubicdissection Marketplace Ottawa Cube listing this week.

A Whole New Level of Puzzle Abuse - Completely Broken Soma

The Soma cube has recently taken a lot of abuse as it’s pieces have been squashed, skewed, shrunk, amputated, and otherwise transmuted.  The latest tragedy is the Completely Broken Soma.  It is the most horriblest puzzle ever excreted from a severely deranged mind.  The scourge to be reviled in the anals of history, loathed by collectors and craftsmen alike.

Yup, if there were truth in puzzle advertising, this would surely accompany the Completely Broken Soma.  After some minor tweaking by Marketing, it will end up with something like:  An heirloom puzzle, surely to be treasured for generations.  It provides a fun challenge that will continue to amaze and amuse you. 

Do we really need another Soma puzzle with broken pieces?  I decided that if I was going to break another Soma, I would do it right once and for all.  The Soma pieces would be so butchered and unrecognizable, that I decided to name this new masterpiece, the Completely Broken Soma.  Each piece would have half of ALL it’s cubies removed requiring the puzzle to have 2 skeletal versions of each piece.  And, of course, you won’t be able to simply join the 2 versions of each piece together.  

Since every piece is half of a Soma piece, there are now 14 pieces.  Ok, this is already a bad idea.  14 pieces is just too many to expect anyone to solve.  Now comes the marketing.  How can we recover from committing this most heinous crime?  How can we salvage this calamity to make it the most desirable puzzle acquisition for 2020?  Noticed how I slipped that proverbial “we” in there? 

Maybe we could glue intersecting pieces into pairs again to get back to 7 pieces.  As it turns out, the pieces of the Completely Broken Soma naturally mate in pairs, but please don’t expect more Completely Broken Somas.  Of course, these 7 pairs look like hybrids of 2 Soma pieces, which they are.  The pairs have anywhere between 1 and 4 half cubes sticking out of them.  In fact, once the cube is assembled, it naturally disassembles into these 7 pairs and you can just treat it as a 7-piece puzzle.

Maybe the half-cubes can be made with exotic woods that make a pattern that provides hints on where the pieces go.  For instance, with 2 types of wood, it could be made into a checkered cube.  Or it could be made with corners of one type of wood, face centers a second type, and edges a third type.  The center can reuse one of the wood types such as the one used for the edges or it can be its own fourth type.  Of course, there is always the possibility of making an even easier version with 27 different types of wood, where only each half-cube and it’s mate would be the same.  This would be a very lovely puzzle and probably within the grasp of most puzzlers.  Who wouldn’t want a copy of that?

It’s not easy to completely break something.  BurrTools choked on this travesty for 18 hours before it finally found a set of pieces that would make a cube and another hour after that to find a cube that could be disassembled.

At this point it was all conjecture on how difficult this puzzle really was, so I made the 2-color version.  10 minutes later, I marked the pieces where the third color would be.  Not long after, I identified and marked the 2 half-cubes that comprise the center cube.  With the, now 4-color version, I was able to solve it pretty quickly.  Yes, I was pretty lazy, and had I been playing with a nicely crafted puzzle, I would have stuck with it longer than my ugly version with post-its stuck all over it.  

It’s amazing how that fourth color makes all the difference. Since there is only one cube with that color, it’s an immediate win and something you can hang your hat on.  Without it, nothing is certain.  My current feeling, is that the 3-colored version probably has the right level of difficulty and the 2 half-cubes that make the center can be provided as a hint if needed.

If you were reading carefully, you noticed that I indicated that this puzzle would be despised by craftsmen as well.  I’m guessing that making the pieces of this puzzle would fall into the difficulty category with all those small gluing surfaces.  My biggest concern was that the pieces would be difficult to make and someone might break them.  As the name implies, the puzzle shouldn’t be broken any further, it’s completely broken as is. 

It may not be obvious, but I specifically designed the pieces so that each glue joint could be clamped.  When I made the pieces for my prototype, I used BurrTools to put it together.  This allowed me to look at a very lumpy looking cube.  Recalling a bit of advice from Stickman, I put the cube in the microwave for a bit to loosen the glue and them clamped it for a few hours.  After unclamping, I had a proper looking cube and a nice set of pieces.  Although my kitchen microwave is my go-to shop tool, this is probably not true for most craftsman.

So now that we finally have a nice design, will you see this puzzle available in the future?  I don’t have a definitive answer to that.  It may be a hard sell to get a craftsman to take this one on.  Of course, a lot of this is driven by demand.  If you would be interested in seeing the Completely Broken Soma made, let me know and I'll check if someone is willing to make it. 

The First of April - Fool’s Cube

It’s the first of April, and we all know what that means.  It’s a time for tricks, pranks, and of course, PUZZLES!  Since this post falls exactly on that magnificent day, I decided to celebrate by creating a little puzzle.  The design criterion was simple.  No, coming up with the design criterion wasn’t simple, the criterion itself was to be simple.  I don’t know why it’s so complicated to describe a simple criterion.

Simple in this context was a 3x3x3 cubic dissection that would be within the capabilities of most wood tinkerers to make.  That provided 27 cubes to work with.  To make it even easier, I decided that it had to be interlocking.  Anyone familiar with 3x3x3 puzzles knows that you really can’t make a difficult interlocking puzzle in that format, even if you wanted to.  Although, I was tempted to add half-cubes and add rotations, I stuck with the design criterion and kept it simple.  However, it still has a nice Aha moment to be enjoyed.

In honor of this fabulous holiday, the puzzle was named Fool’s Cube.  Since I haven’t started working in the garage shop yet, I made the prototype from some Cherry and White Oak pieces left over from past projects.  I was 3 cubes short of being able to make it all in Cherry.  Since there are only 4 wooden pieces, I decided to drill a hole in each and put them on a keychain.  This way, I can easily carry the pieces together and hand them to someone to solve.  I didn’t have an appropriate keychain and the one that I made is too large.  I’ll need to shop around for a more suitable one and plan on getting one of those nylon coated stainless steel wire keychains.

Fools’ Cube has a difficulty of 1.2.1 and there are no rotations.  You could put it in BurrTools and it will not only provide the assembly but show you step-by-step how to put it together, but don’t waste your time doing that.  Just build one and solve it on your own.  It will take you a lot less time solving it than building it.  If you do make one to try, you should time yourself to determine how long it takes you to put it together.  Most of you will do it in a couple of minutes.  Let me know how you do.  It took my wife a minute and a half.

Inspiration from Grandchildren - Little Kenny and Wooden Puzzles

How would you like to take a journey through 20 different must-have classic puzzle designs by world-renowned puzzle designers?  Along the way, the secrets of how to make them yourself will be revealed.

Several years ago, my good friend and master craftsman, Brian Menold, informed me that he was writing the definitive book on how to make wooden puzzles and asked if I would like to contribute a design.  Even before I knew of the world-class puzzle designers that would be included, I readily agreed.  I later found out that the book included designs from Stewart Coffin, Jos Bergmans, Yavuz Demirhan, Stéphane Chomine, Primitivo Familiar Ramos, Tom Jolly, and of course Brian Menold.  The cognoscenti of puzzledom.  Fortunately, I didn’t have the pressure of knowing the other contributors beforehand.

Brian’s guidance to me was that the book, called Wooden Puzzles, was targeting entry level woodworkers and he was looking for a simple design.  I translated simple to mean a puzzle based on a cubic dissection with rectilinear moves and a fairly small form factor, i.e., no larger than a 4x4x4 cube.

At about the same time that Brian asked for my contribution, along came my first grandson, Kenny.  He is a continual source of puzzlement and wonder.  When my grandson was 4, I informed him on some random sunny afternoon that he would be starting school the following year.  He looked at me, and in no uncertain terms said, “My mom said I don’t have to go to school”.   Trying my best to realign his thinking, I told him that everyone had to go to school.  Unfazed, he peered over at me again and replied, “I don’t need to go to school.  My job is inspiration!”  Well, how do you argue with that?  Needless to say, this post is about the puzzle that was inspired by Little Kenny.

The initial version of Little Kenny that was included in Wooden Puzzles is comprised of 4 pieces in a 4x4x3 format.  Only rectilinear moves are required and the level of difficulty is 5.1.1.  I was very happy with this design and thought that it was an excellent fit for the book.  Since the book has been released, I’ve received feedback from a couple of woodworkers with Wooden Puzzles and they loved Little Kenny.

Brian did an amazing job writing Wooden Puzzles.  Not only is it informative, but it is crammed full of pictures of puzzles, tools, jigs, and various types of wood.  The book is comprised of 4 main sections.  The first section provides an overview of tools for puzzle making, selecting wood for puzzles, and jigs for making puzzles.  The second section is the majority of the book and describes in detail how to make the 20 puzzles covered.  By the time you get through all 20, you should have a good understanding of the woodworking basics required to make these types of puzzles.  The following section provides some recommendations for taking your puzzle making to the next level.  Alas, the last section shows the solution for solving each of the puzzles covered in the book, but I know that you won’t be tempted to look.

Although Brian indicated that his book was for beginning woodworkers, I believe that it is suitable for woodworkers at all levels.  There are great little nuggets of information for everyone.  I pulled out my copy of Wooden Puzzles as I was writing this post and as I was flipping through it, I realized that it was time to read it again in preparation for making this year’s puzzle prototypes.  The book may also be of interest to puzzle collectors interested in the process of creating the puzzles that they collect.  Just don’t read the solutions to the puzzles provided in the back of the book.

Shortly after providing the initial Little Kenny design to Brian, I decided to make a more difficult version for the upcoming IPP35.  I was able to split one of the blocks to require rotational moves in the solution, thus becoming the first puzzle in the half-cube series.  I brought my updated Little Kenny prototype to IPP35 and it was well received.  Just like my grandson, it’s small size with only 4 pieces makes it look fairly innocuous but it does have a little bite to it.  And no, the solution provided in Wooden Puzzles won’t help you with the updated version.

After IPP35, Little Kenny was produced by the world-class craftsman, Tom Lensch.  The pictures in this post are of Tom’s version made with Jatoba.  With the successful release at IPP35, I decided to enter it in the Nob Yoshigahara Puzzle Design Competition the following year at IPP36 where it received the award for …. nothing!  Oh well.  It was up against some pretty stiff competition like Chain Store (Yanked My Chain - Chain Store) and Bitten Biscuits (Food For Thought - Bitten Biscuits).

You should get a copy of Wooden Puzzles.  It is available on Amazon here.  Then you can make your own copy of the original Little Kenny design.  If you want a copy of the updated half-cube version of Little Kenny, they will be available soon from Brian Menold at Wood Wonders.

A Christmas Present For You – Ultimate Penultimate Burr Box Set Challenge

 

Merry Christmas!  Hopefully, Santa left you many puzzles under the tree.  And if you don’t celebrate Christmas, a Happy Whatever You Celebrate to you!

It’s been 6 months since the Penultimate Burr Box Set was released by Cubicdissection.  I figured that most people have already solved all 898 of the puzzle challenges by now and that the sets were starting to collect a layer of dust.  Instead of generating hundreds of additional 6-piece burr challenges, I decided to determine if I could find a burr puzzle that required more than 6 pieces.  In essence, I was looking for the ultimate Penultimate Burr Box Set challenge.

The picture above shows the result of that search.  This shape can be constructed with 2 different sets of pieces, each with a unique solution and a 1.2.2.2 level of difficulty.  However, the only difference between the 2 sets is the substitution of one piece and the substituted piece is only different by 1 cubie.  In effect, there is really only one puzzle.  The pieces used are deferred to the bottom of the post in case you wanted to figure out which 8 of the 27 pieces are required to build the shape as part of the solving process.  For the sane readers, just keep reading.

To come up with this bonus, I experimented with several shapes using BurrTools until I found this one.  Here is a timeline of my experience testing it:

• 0 minutes: With 8 pieces, this looks like a daunting task.  Complex Burrs with more than 6 pieces sometimes use different colors for pieces based on their orientation to help the solving process.  Of course, all these pieces are of the same type of wood and nothing special has been done to aid the solving process.  Then again, this puzzle wasn’t specifically designed to be difficult by an evil (I use this word in the most affectionate way possible) puzzle designer.
• 5 minutes: OK, I think that I know which pieces are the 4 that go together, which I will refer to as frame pieces, and the 4 that cross each other inside it, which I will refer to as cross pieces.  I already have 7 pieces in place.  How hard can it be to add 1 more?  I’ll probably have to shuffle some pieces around, but it shouldn’t be a big deal.  I’m also pretty sure what the last piece to be added is.
• 10 minutes: I now have 7 pieces where it looks like the last piece would fit inside.  However, there are 48 possible assemblies and only 1 can be constructed.  After some fiddling around, this one doesn’t seem to be the lucky one.

• 

  Wrong Orientation!

  15 minutes: I’ve got them all together!  Wait a minute.  They aren’t in the correct orientation.  However, I’m pleased to have found another symmetric target shape.  I decided to check out my clever new shape in BurrTools.  In seconds, BurrTools started laughing and informed me that there at 92 different ways to construct that shape with those pieces.  92 different ways!  If you dropped the pieces on the table they would probably fall into that shape.  OK, so let’s call that the easy, warm-up objective.
• 1 hour: Uh, maybe all this trial and error isn’t the way to go.  I keep doing the same thing over and over.  Time to break down and start thinking about it.  There are 48 different ways to put the 4 frame pieces together and then there are 24,576 ways to place the 4 cross pieces inside, resulting in 1,179,648 different combinations and that is assuming that I was correct in the division of pieces.  Given these numbers, most puzzlers take the lazy way out and start thinking about how to solve the problem.  It seems that 2 of the cross pieces have to work together and this appears to lock up the 4 frame pieces where you can’t add the other 2 cross pieces.
• 1 hour, 15 minutes:  Solved!  For me, the trick was figuring out what the second to last piece to be added was and arranging all the other pieces so that this move could be accomplished.

Is this a good puzzle?  Yes and no.  It was a lot of fun to work on and well worth doing.  If you have the Penultimate Burr Box Set, definitely pull it back out, dust it off, and enjoy this ultimate challenge.  It’s a great puzzle!  If you don’t have the set and someone offers to sell you this puzzle, don’t buy it.  It’s a terrible puzzle!  This puzzle was not specifically designed to be a clever 8-piece burr puzzle and would be scoffed at by any discerning puzzle collector.  It’s fine as a puzzle challenge in a large burr set, but not good enough to justify as a standalone puzzle.

Any excuse to pull out the Penultimate Burr Box Set is a good one.  The set is beautiful and well crafted.  The pieces are spot on and a pleasure to play with.  Cubicdissection did a fantastic job making these sets and I always enjoy spending time with it.

The pieces required to make the ultimate Penultimate Burr Box Set challenge puzzle are: 5, 6, 7, 8, 9, 10, 15, and 12 (or 17 instead of 12).